class user{
    // new methods don't care about this anymore so this will get deleted
    public $logs = array();

    // ... irrelevant methods left out ...

    // old method
    public function user_search($db_connection, $user_id=null, $username=null){
      $result = false;
      if($user_id == null && $username == null)
        $this->logs[] = "No information to search on has been found.";
      elseif($db_connection == false)
        $this->logs[] = "Something went wrong with the database.";
      else{
        $this->logs[] = "Searching the user in the database.";
        $query_user_search = $db_connection->prepare('SELECT * FROM users WHERE user_username=:user_username OR user_id=:user_id');
        $query_user_search->bindValue(':user_username', $username, PDO::PARAM_STR);
        $query_user_search->bindValue(':user_id', $user_id, PDO::PARAM_STR);
        $query_user_search->execute();
        if($result = $query_user_search->fetch())
          $this->logs[] = "We found the user.";
        else
          $this->logs[] = "We didn't find the user.";
      }
      return $result;
    }

    // new method
    public function user_search_info($db_con, $user_id=null, $user_username=null){
      $query_user_search_info = $db_con->prepare('SELECT * FROM users WHERE user_username=:user_username OR user_id=:user_id');
      $query_user_search_info->bindValue(':user_id', $user_id, PDO::PARAM_STR);
      $query_user_search_info->bindValue(':user_username', $user_username, PDO::PARAM_STR);
      $query_user_search_info->execute();
      return $query_user_search_info->fetch();
    }
  }

public function return_user_search_info($search_user_variable, $search_user_value)
{
  $user_search_info = false;
  if($search_user_variable == "user_id")
    $user_search_info = $this->user->user_search_info($this->db_con, $search_user_value, "");
  elseif($search_user_variable == "user_username")
    $user_search_info = $this->user->user_search_info($this->db_con, "", $search_user_value);
  return $user_search_info;
}